This resource contains a shapefile of HUC-8 (eight digit Hydrologic Unit Codes) for the Continental United States (CONUS).

The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit data consistent with the national criteria for delineation and resolution. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as stated by the "Federal Standards and Procedures for the National Watershed Boundary Dataset (WBD)" “Standard” (http://pubs.usgs.gov/tm/11/a3/). Watershed boundaries are determined solely upon science-based hydrologic principles, not favoring any administrative boundaries or special projects, nor particular program or agency. This dataset represents the hydrologic unit boundaries to the 12-digit (6th level) for the entire United States. Some areas may also include additional subdivisions representing the 14- and 16-digit hydrologic unit (HU). At a minimum, the HUs are delineated at 1:24,000-scale in the conterminous United States, 1:25,000-scale in Hawaii, Pacific basin and the Caribbean, and 1:63,360-scale in Alaska, meeting the National Map Accuracy Standards (NMAS). Higher resolution boundaries are being developed where partners and data exist and will be incorporated back into the WBD. WBD data are delivered as a dataset of polygons and corresponding lines that define the boundary of the polygon. WBD polygon attributes include hydrologic unit codes (HUC), size (in the form of acres and square kilometers), name, downstream hydrologic unit code, type of watershed, non-contributing areas, and flow modifications. The HUC describes where the unit is in the country and the level of the unit. WBD line attributes contain the highest level of hydrologic unit for each boundary, line source information and flow modifications.

The Watershed Boundary Dataset (WBD) is a seamless, national hydrologic unit dataset. Simply put, hydrologic units represent the area of the landscape that drains to a portion of the stream network. More specifically, a hydrologic unit defines the areal extent of surface water drainage to an outlet point on a dendritic stream network or to multiple outlet points where the stream network is not dendritic. A hydrologic unit may represent all or only part of the total drainage area to an outlet point so that multiple hydrologic units may be required to define the entire drainage area at a given outlet. Hydrologic unit boundaries in the WBD are determined based on topographic, hydrologic, and other relevant landscape characteristics without regard for administrative, political, or jurisdictional boundaries. The WBD seamlessly represents hydrologic units at six required and two optional hierarchical levels.The hydrologic units (HU) in the WBD form a standardized system for organizing, collecting, managing, and reporting hydrologic information for the nation. The HU in the WBD are arranged in a nested, hierarchical system with each HU in the system identified using a unique code. Hydrologic unit codes (HUC) are developed using a progressive two-digit system where each successively smaller areal unit is identified by adding two digits to the identifying code the smaller unit is nested within. WBD contains eight levels of progressive hydrologic units identified by unique 2- to 16-digit codes. The dataset is complete for the United States to the 12-digit hydrologic unit. The 14- and 16-digit hydrologic units are optional and are not complete for the nation. Efforts are ongoing to complete 10- and 12-digit unit delineations within 8-digit hydrologic units extending across the U.S. – Canada border. Additional information about this effort and access to data is linked on the “resources” section on this page. A similar effort is complete for the 10- and 12-digit units extending across the U.S. – Mexico border.More information can be found here: https://www.usgs.gov/core-science-systems/ngp/national-hydrography/watershed-boundary-dataset?qt-science_support_page_related_con=4#qt-science_support_page_related_con

🇺🇸 미국 English The Watershed Boundary Dataset (WBD) is a seamless, national hydrologic unit dataset. Hydrologic units represent the area of the landscape that drains to a portion of the stream network. (https://www.usgs.gov/national-hydrography/watershed-boundary-dataset) It is maintained by the U.S. Geological Survey (USGS) in partnership with the states. The Department of Water Resources is the steward for the California portion of this dataset.The hydrologic units (HU) in the WBD form a standardized system for organizing, collecting, managing, and reporting hydrologic information for the nation. The HUs in the WBD are arranged in a nested, hierarchical system with each HU in the system identified using a unique code. Hydrologic unit codes (HUC) are developed using a progressive two-digit system where each successively smaller areal unit is identified by adding two digits to the identifying code the smaller unit is nested within. WBD contains eight levels of progressive hydrologic units identified by unique 2- to 16-digit codes. The dataset is complete for the United States to the 12-digit hydrologic unit. The 8-digit level unit is often referred to as HUC8 and is a commonly used reference framework for planning and environmental assessment. This particular version of the dataset was created by downloading the CA State extract of the National Hydrography Dataset from the USGS website https://www.usgs.gov/national-hydrography/access-national-hydrography-products and then performing a geoprocessing operation in ArcGIS Pro software to clip the HUC8s at the state of California political boundary. (https://data.cnra.ca.gov/dataset/california-county-boundaries2). A web map service was created with this dataset, but at it's original digitized resolution it can take a long time to render in a web map application. This dataset is a simplified version, created by use of the ArcGIS Simplify Polygon tool with the Douglas-Peucker Line simplification algorithm, reducing the vertex count from 1,095,449 to 9108. This dataset was reprojected from the original NAD 83 Geographic Coordinate System to WGS 1984 Web Mercator auxiliary sphere for use in web map applications. Any questions about this dataset may be sent to jane.schafer-kramer@water.ca.gov

The Climate Resilience Information System (CRIS) provides data and tools for developers of climate services. This layer has historical variables in decadal increments from 1950 to 2020 derived from historical observations of air temperature and precipitation. The variables included are:Annual average daily maximum temperature (°F) Annual average daily temperature (°F) Annual average daily minimum temperature (°F) Annual single highest maximum temperature (°F) Annual single lowest minimum temperature (°F) Annual average summertime (June, July, August) temperature (°F) This layer uses data from the Livneh gridded precipitation and other meteorological variables for continental US, Mexico and southern Canada. Further processing by Esri is explained below.For each variable, there are mean values for the defined respective geography: counties, tribal areas, HUC-8 watersheds. The process for deriving these summaries is available from the CRIS Website’s About the Data. Other climate variables are available from the CRIS Data page. Additional geographies, including Alaska, Hawai’i and Puerto Rico will be made available in the future.GeographiesThis layer provides historic values for three geographies: county, tribal area, and HUC-8 watersheds.County: based on the U.S. Census TIGER/Line 2022 distribution. Tribal areas: based on the U.S. Census American Indian/Alaska Native/Native Hawaiian Area dataset 2022 distribution. This dataset includes federal- and state-recognized statistical areas.HUC-8 watershed: based on the USGS Washed Boundary Dataset, part of the National Hydrography Database Plus High Resolution. Time RangesHistoric climate threshold values (e.g. Days Over 90°F) were calculated for each year from 1950 to 2020. To ensure the layer displays time correctly, under 'Map properties' set Time zone to 'Universal Coordinated Time (UTC)' and under 'Time slider options' set Time intervals to '1 Decade'.Data CitationLivneh, B., T. J. Bohn, D. W. Pierce, F. Munoz-Arriola, B. Nijssen, R. Vose, D. R. Cayan, and L. Brekke, 2015: A spatially comprehensive, hydrometeorological data set for Mexico, the U.S., and Southern Canada 1950 - 2013. Scientific Data, 2, https://doi.org/10.1038/sdata.2015.42.Data ExportExporting this data into shapefiles, geodatabases, GeoJSON, etc is enabled.

Rasters of positive openness for the 53 hydrologic unit code (HUC) 8 watersheds in the state of North Carolina. Positive openness uses a line-of-sight approach to measure the surrounding eight zenith angles viewed above the landscape surface out to a specified distance. The central cells gets and average of the eight angles. An angle of 90 degrees would indicate a flat surface, while angles less than 90 degrees indicate a concave surface. Positive openness was calculated with the Relief Visualization Toolbox (https://iaps.zrc-sazu.si/en/rvt#v, Kokalji et al., 2011; Zakšek et al., 2011) using light detection and ranging (lidar) derived digital elevation models (DEM) with a resolution of 10 ft. (~3m). A length scale of 60 ft.(6 pixels) was used to search surrounding terrain elevations in the eight cardinal directions.

This data set is a complete digital hydrologic unit boundary layer to the Subbasin (8-digit) 8th level for the State of New Mexico. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "FGDC Proposal, Version 1.0 - Federal Standards For Delineation of Hydrologic Unit Boundaries 3/01/02"(http://www.ftw.nrcs.usda.gov/huc_data.html). Polygons are attributed with hydrologic unit codes for 4th level sub-basins, 5th level watersheds, 6th level subwatersheds, name, size, downstream hydrologic unit, type of watershed, non-contributing areas and flow modification. Arcs are attributed with the highest hydrologic unit code for each watershed, linesource and a metadata reference file.

The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit data consistent with the national criteria for delineation and resolution. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as stated by the "Federal Standards and Procedures for the National Watershed Boundary Dataset (WBD)" “Standard” (http://pubs.usgs.gov/tm/11/a3/). Watershed boundaries are determined solely upon science-based hydrologic principles, not favoring any administrative boundaries or special projects, nor particular program or agency. This dataset represents the hydrologic unit boundaries to the 12-digit (6th level) for the entire United States. Some areas may also include additional subdivisions representing the 14- and 16-digit hydrologic unit (HU). At a minimum, the HUs are delineated at 1:24,000-scale in the conterminous United States, 1:25,000-scale in Hawaii, Pacific basin and the Caribbean, and 1:63,360-scale in Alaska, meeting the National Map Accuracy Standards (NMAS). Higher resolution boundaries are being developed where partners and data exist and will be incorporated back into the WBD. WBD data are delivered as a dataset of polygons and corresponding lines that define the boundary of the polygon. WBD polygon attributes include hydrologic unit codes (HUC), size (in the form of acres and square kilometers), name, downstream hydrologic unit code, type of watershed, non-contributing areas, and flow modifications. The HUC describes where the unit is in the country and the level of the unit. WBD line attributes contain the highest level of hydrologic unit for each boundary, line source information and flow modifications.

NOTE: This dataset contains California-vicinity HUC8 boundaries as represented in the Watershed Boundary Dataset (WBD) included with the California-vicinity National Hydrography Dataset (NHD) with version date indicated elsewhere in this metadata. Much of this dataset's metadata was adapted from the nationwide WBD metadata.The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit data consistent with the national criteria for delineation and resolution. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as stated by the "Federal Standards and Procedures for the National Watershed Boundary Dataset (WBD)" "Standard" (https://pubs.usgs.gov/tm/11/a3/). Watershed boundaries are determined solely upon science-based hydrologic principles, not favoring any administrative boundaries or special projects, nor particular program or agency. This dataset represents the hydrologic unit boundaries to the 12-digit (6th level) for the entire United States. Some areas may also include additional subdivisions representing the 14- and 16-digit hydrologic unit (HU). At a minimum, the HUs are delineated at 1:24,000-scale in the conterminous United States, 1:25,000-scale in Hawaii, Pacific basin and the Caribbean, and 1:63,360-scale in Alaska, meeting the National Map Accuracy Standards (NMAS). Higher resolution boundaries are being developed where partners and data exist and will be incorporated back into the WBD. WBD data are delivered as a dataset of polygons and corresponding lines that define the boundary of the polygon. WBD polygon attributes include hydrologic unit codes (HUC), size (in the form of acres and square kilometers), name, downstream hydrologic unit code, type of watershed, non-contributing areas, and flow modifications. The HUC describes where the unit is in the country and the level of the unit. WBD line attributes contain the highest level of hydrologic unit for each boundary, line source information and flow modifications.

This polygon file depicts USGS Hydrologic Unit Code 8 (HUC8) boundaries intersecting Kansas. See https://www.usgs.gov/national-hydrography/national-hydrography-dataset and https://www.usgs.gov/national-hydrography/watershed-boundary-dataset for more information.The only modification to the data by KBS was the addition of a new attribute column containing a numerically formatted HUC identification number.Shapefile download: https://ku.maps.arcgis.com/home/item.html?id=a5f861d4cfce43d0a73bb5f3b00dce5dSource data acquisition date: January 22, 2023Source data download directory: https://prd-tnm.s3.amazonaws.com/index.html?prefix=StagedProducts/Hydrography/NHD/State/GDB/Source data download file: NHD_H_Kansas_state_GDB.zip

This data release consists of the data used to develop SPAtially Referenced Regression On Watershed(SPARROW) attributes models for estimating loads of total phosphorus and total nitrogen in Tennessee streams. These data support the publication containing the Tennessee SPARROW models results (Hoos and others, 2019) and include model input used in the South Atlantic-Gulf Drainages and Tennessee River Basin (SAGT) nutrient SPARROW models (Hoos and McMahon, 2009; Garcia and others, 2011) as well as model input for river basins in Tennessee not included in the domain of the published SAGT SPARROW models. Also included in this data release are model coefficients, the software required to execute the Tennessee SPARROW models, and the model output for all streams in Tennessee. Each data set is listed in this data release with an accompanying file containing metadata for the dataset. For additional details, please refer to the README.txt file.

The United States is divided and sub-divided into successively smaller hydrologic units which are classified into four levels: regions, sub-regions, accounting units, and cataloging units. The hydrologic units are arranged or nested within each other, from the largest geographic area (regions) to the smallest geographic area (cataloging units). Each hydrologic unit is identified by a unique hydrologic unit code (HUC) consisting of two to eight digits based on the four levels of classification in the hydrologic unit system. A shapefile (or geodatabase) of watersheds for the state of Alaska and parts of western Canada was created by merging two datasets: the U.S. Watershed Boundary Dataset (WBD) and the Government of Canada's National Hydro Network (NHN). Since many rivers in Alaska are transboundary, the NHN data is necessary to capture their watersheds. The WBD data can be found at https://catalog.data.gov/dataset/usgs-national-watershed-boundary-dataset-wbd-downloadable-data-collection-national-geospatial- and the NHN data can be found here: https://open.canada.ca/data/en/dataset/a4b190fe-e090-4e6d-881e-b87956c07977. The included python script was used to subset and merge the two datasets into the single dataset, archived here.

The United States is divided and sub-divided into successively smaller hydrologic units which are classified into four levels: regions, sub-regions, accounting units, and cataloging units. The hydrologic units are arranged or nested within each other, from the largest geographic area (regions) to the smallest geographic area (cataloging units). Each hydrologic unit is identified by a unique hydrologic unit code (HUC) consisting of two to eight digits based on the four levels of classification in the hydrologic unit system.https://water.usgs.gov/GIS/huc.html

This EnviroAtlas dataset contains polygons depicting the number of watershed-level market-based programs, referred to herein as markets, in operation per 8-digit HUC watershed throughout the United States. The data were collected via surveys and desk research conducted by Forest Trends' Ecosystem Marketplace during 2014 regarding markets operating to protect watershed ecosystem services. Utilizing these data, the number of water market coverage areas overlaying each HUC8 watershed were calculated to produce this dataset. Only water markets identified as operating at the watershed level (i.e., single or multiple watersheds define the market boundaries) were included in the count of water markets per HUC8 watershed. Excluded were water markets operating at the national, state, county, or federal lands level and all water projects. Attribute data include the watershed's 8-digit hydrologic unit code and name, in addition to the watershed-level water market count associated with the watershed. This dataset was produced by Forest Trends' Ecosystem Marketplace to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

The NHD is a national framework for assigning reach addresses to water-related entities, such as industrial discharges, drinking water supplies, fish habitat areas, wild and scenic rivers. Reach addresses establish the locations of these entities relative to one another within the NHD surface water drainage network, much like addresses on streets. Once linked to the NHD by their reach addresses, the upstream/downstream relationships of these water-related entities--and any associated information about them--can be analyzed using software tools ranging from spreadsheets to geographic information systems (GIS). GIS can also be used to combine NHD-based network analysis with other data layers, such as soils, land use and population, to help understand and display their respective effects upon one another. Furthermore, because the NHD provides a nationally consistent framework for addressing and analysis, water-related information linked to reach addresses by one organization (national, state, local) can be shared with other organizations and easily integrated into many different types of applications to the benefit of all. This dataset represents NHD as published by USGS on 4/27/2019.

(Link to Metadata) WaterHydro_WBD8VT includes Subbasins within Vermont (HUC8 level hydrologic unit boundaries). The boundaries are consistent with Vermont's Hydrography Dataset (VHD).

This Watershed Boundary Dataset (WBD) is a complete 1:24,000 scale digital hydrologic unit (HU) boundary layer for the 4th level subbasin (8 digit), the 5th level watershed (10 digit), and the 6th level (12-digit) subwatershed for the state of California.This dataset consists of georeferenced digital data and associated attributes created in accordance with the "USGS National Map Accuracy Standards and the NRCS Federal Standards for Delineation of Hydrologic Unit Boundaries, 10/01/04"
(ftp://ftp-fc.sc.egov.usda.gov/NCGC/products/watershed/hu-standards.pdf).

The dataset was developed by digitizing watershed and subwatershed boundary lines using 1:24,000-scale digital raster graphics (DRG), high-resolution digital watershed datasets, a high-resolution National Hydrography Dataset (NHD) at 1:24,000-scale, and 1:250,000-scale draft hydrologic boundary lines. A 30-meter National Elevation Dataset (NED) was used to produce the 1:250,000-scale preliminary draft boundaries, as well as a hillshade layer for additional reference.
Some draft catchments (watersheds/subwatersheds) were also created with Watershed Boundary Dataset tools (ArcHydro Tools, Version 9), using the NED for terrain analysis and the NHD for determining stream flow direction.

Polygons are attributed with the following: hydrologic unit codes for 4th level sub-basins, 5th level watersheds, and 6th level subwatersheds; HU sizes (in acres); states containing the HUs; non-contributing areas; downsteam hydrologic units; 5th and 6th level names; type of HUs (standard, frontal, etc.); flow modifications; and Geographic Names Information System (GNIS) identification numbers. Lines are attributed with the highest hydrologic unit code for each (sub)watershed, linesource, and a metadata reference file.

This data set is a complete digital hydrologic unit boundary layer to the Subbasin (8-digit) 8th level for the State of New Mexico. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "FGDC Proposal, Version 1.0 - Federal Standards For Delineation of Hydrologic Unit Boundaries 3/01/02"(http://www.ftw.nrcs.usda.gov/huc_data.html). Polygons are attributed with hydrologic unit codes for 4th level sub-basins, 5th level watersheds, 6th level subwatersheds, name, size, downstream hydrologic unit, type of watershed, non-contributing areas and flow modification. Arcs are attributed with the highest hydrologic unit code for each watershed, linesource and a metadata reference file.

This dataset is a representation of Hydrologic Unit Code (HUC) boundaries at the HUC8 level compiled from U.S. Geological Survey (USGS) National Hydrography Dataset (NHD) and U.S. Department of Agricultural (USDA) National Resources Conservation Services (NRCS) Watershed Boundary Dataset (WBD) sources.The Watershed and Subwatershed hydrologic unit boundaries (WSB)provide a uniquely identified and uniform method of subdividing large drainage areas. The smaller sized 6th level sub-watersheds (up to 250,000 acres) are useful for numerous application programs supported by a variety of local, State, and Federal Agencies.

In order to better understand the combined impacts of climate change and spatially identify where changes are anticipated to be most extreme, we developed a climate change vulnerability map for the Midwest Region. The vulnerability map is watershed-based (Hydrologic Unit Code-8) and combines fifteen climate change indicators evenly divided into three categories: temperature, precipitation, and hydrology that were selected by resource managers working in Region 3 of the United States Fish and Wildlife Service. The projected change in each of these indicators from the baseline period (1986-2005) to the future period (2040-2059) was aggregated into a composite score for each watershed. Landscape-scale metrics reflective of a watershed’s adaptive capacity were combined with the climate change impact indicators to produce a vulnerability score. We found sub-regional variation in vulnerability to climate change with the greatest vulnerability in Iowa, central Illinois, and northwest Oh ...

Source data found here: https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServerEach drainage area is considered a Hydrologic Unit (HU) and is given a Hydrologic Unit Code (HUC) which serves as the unique identifier for the area. HUC 2s, 6s, 8s, 10s, & 12s, define the drainage Regions, Subregions, Basins, Subbasins, Watersheds and Subwatersheds, respectively, across the United States. Their boundaries are defined by hydrologic and topographic criteria that delineate an area of land upstream from a specific point on a river and are determined solely upon science based hydrologic principles, not favoring any administrative boundaries, special projects, or a particular program or agency. The Watershed Boundary Dataset is delineated and georeferenced to the USGS 1:24,000 scale topographic basemap.Hydrologic Units are delineated to nest in a multi-level, hierarchical drainage system with corresponding HUCs, so that as you move from small scale to large scale the HUC digits increase in increments of two. For example, the very largest HUCs have 2 digits, and thus are referred to as HUC 2s, and the very smallest HUCs have 12 digits, and thus are referred to as HUC 12s.Dataset SummaryPhenomenon Mapped: Watersheds in the United States, as delineated by the Watershed Boundary Dataset (WBD)Geographic Extent: Contiguous United States, Alaska, Hawaii, Puerto Rico, Guam, US Virgin Islands, Northern Marianas Islands and American SamoaProjection: Web MercatorUpdate Frequency: AnnualVisible Scale: Visible at all scales, however USGS recommends this dataset should not be used for scales of 1:24,000 or larger.Source: United States Geological SurveyPublication Date: January 7, 2025What can you do with this layer?This layer is suitable for both visualization and analysis acrossthe ArcGIS system. This layer can be combined with your data and other layers from the ArcGIS Living Atlas of the World in ArcGIS Online and ArcGIS Pro to create powerful web maps that can be used alone or in a story map or other application. Because this layer is part of the ArcGIS Living Atlas of the World it is easy to add to your map:In ArcGIS Online, you can add this layer to a map by selecting Add then Browse Living Atlas Layers. A window will open. Type "Watershed Boundary Dataset" in the search box and browse to the layer. Select the layer then click Add to Map. In ArcGIS Pro, open a map and select Add Data from the Map Tab. Select Data at the top of the drop down menu. The Add Data dialog box will open on the left side of the box, expand Portal if necessary, then select Living Atlas. Type "Watershed Boundary Dataset" in the search box, browse to the layer then click OK.